How does Jandor's Ring work with modern Magic rules?The nice thing about Jandor's Ring from a rules perspective is that the discard is a cost, so if you lose track of the last drawn card a judge can just declare that the cost can't be paid. With Sylvan Library, on the other hand, it's possible to enter a broken game state where you can't identify which cards to put back and you don't have enough life to pay to keep them.